(Submitted February 09, 2002)
Are there any stars larger than our solar system?
Thank you for your question. If we consider the size of the solar
system as the distance of the Sun to the furthest planet, Pluto, then
the solar system is roughly eight thousand times larger than the
radius of the Sun. The largest stars we know about are called red
supergiant stars (there is a relatively nearby one called
Betelgeuse). The largest red supergiant we know of is in the binary
system VV Cephei, and is close to four thousand solar radii. This is
large enough to encompass the orbits of Mercury, Venus, Earth, Mars,
and Jupiter; but makes it not quite halfway out to Pluto.
-- Michael Loewenstein and Amy Fredericks for "Ask an Astrophysicist"